For any one or more of the foregoing patents, to the extent that any liquid feed might be involved, the same problems and difficulties to which the present invention is directed, would be present with any one or more of the foregoing prior art patents--which are not directed to the present invention. Accordingly, inaccuracies that the present invention is directed to correct, could be and are likely involved in the practice of the prior inventions.
More particularly, the present invention can be better understood and appreciated by becoming aware of problems that in fact heretofore have plagued the industrial practice of consistently filling diverse receptacles of the same or differing desired volumes with repetitive accurately measured and fed metered volumes of liquid(s) to one vessel alone and/or to a plurality of vessels through a common and/or branched liquid feed flow-conduit(s). First of all, wear and tear and required maintenance and/or the lack thereof to metering pumps, such as typical (but not exclusively) servo pump(s) can and does cause considerable immediate and/or eventual differences in volumes of actual feed-flow monitored and feed therethrough. Even apparently identical pumps often do not consistently have the same nor exact metering capabilities to one another.
However, more common and disruptive problems of consistently inaccurate collected volume(s) of liquid(s) arise from hydrodynamics, or equivalent flow dynamics for non-aqueous liquids, when pumped through irregularly shaped conduit(s) and/or past a series of bends (turns) therein, and differences in flow characteristics based on conduits of different diameters, or of two or more conduits in series of varying inside diameters, taken with difference incurred by different types of metering pump(s). Also, if there are two or more separate outlet valves fed from a common feed conduit, flow dynamics and flow through each of the outlet valves varies considerably depending upon how many of the outlet valves are concurrently open with liquid flowing therethrough, as well as dependent upon potential different rates of flow through two or more of the concurrently open valves permitting concurrent flows. When as is factually the case, the problems exist with even solely a single outlet valve for a consistent always-the-same extent of being a partially or otherwise a totally open valve, the problems--as can be appreciated from the preceding discussion, are compounded geometrically by increasing numbers of outlet valve open concurrently, together with aforestated problems of securing accurate metering where the conduit inside diameter is not standard and/or varies along the way, and/or with bends in the conduit, etc. In the Pharmaceutical and other technical tests for which proven accuracy is required by government regulations, including that of ascertaining exact quantities of tablet dissolving reagent used in dissolving tablets for tests ascertaining dissolution rates of tables used in the pharmaceutical industry, exact and reliable measurements available by the present invention have not heretofore existed to the extent desired and required.